Featured Research

from universities, journals, and other organizations

AIDS May Partly Be The Consequence Of An Evolutionary Accident

Date:
April 3, 2008
Source:
Society for General Microbiology
Summary:
AIDS, a fatal disease in humans, may partly be the consequence of an evolutionary accident. Previous studies have established that one of the key differences between the way HIV-1 behaves in humans and closely related SIVs behave in monkeys is that when humans are infected with HIV-1 the immune system becomes highly stimulated. This means critical defense cells called helper T cells are continuously activated and die more quickly than usual.

AIDS, a fatal disease in humans, may partly be the consequence of an evolutionary accident, scientists explained April 1, 2008 at the Society for General Microbiology's 162nd meeting being held at the Edinburgh International Conference Centre.

"AIDS is a deadly disease in people that is caused by human immunodeficiency virus (HIV). But similar viruses such as simian immunodeficiency virus (SIV), which infects monkeys, usually don't cause disease in their natural monkey hosts," says Professor Frank Kirchhoff from the University of Ulm in Germany.

Previous studies have established that one of the key differences between the way HIV-1 behaves in humans and closely related SIVs behave in monkeys is that when humans are infected with HIV-1 the immune system becomes highly stimulated. This means critical defence cells called helper T cells are continuously activated and die more quickly than usual.

The researchers found that the Nef protein of most SIVs removes a molecule from the cell surface that is critical to make T cells responsive to stimulation. This most likely limits the negative effects otherwise caused by the chronically strong immune response. However, Nef proteins in HIV-1 and its closest related SIVs lack this protective function, according to Professor Kirchhoff.

In natural SIV infections in monkeys, the ability of the Nef protein to remove a specific receptor, named CD3, from the infected cell's surface may help the host animal to maintain a functional immune system, which means that it can still fight off other diseases. Only the Nef proteins of HIV-1 and its immediate SIV relatives do not perform this function.

"We suspect that this evolutionary loss of a protective function of Nef may contribute to the high virulence of HIV-1 in humans" says Prof Kirchhoff. "Well adapted viruses don't kill their hosts."

The team will examine whether SIVs carrying Nef genes artificially made incapable of limiting T cell activation might become more pathogenic in their natural monkey hosts. The group will also examine whether Nef variation among HIV-2 strains might explain differences in the rate of progression to disease in infected humans.


Story Source:

The above story is based on materials provided by Society for General Microbiology. Note: Materials may be edited for content and length.


Cite This Page:

Society for General Microbiology. "AIDS May Partly Be The Consequence Of An Evolutionary Accident." ScienceDaily. ScienceDaily, 3 April 2008. <www.sciencedaily.com/releases/2008/03/080331223840.htm>.
Society for General Microbiology. (2008, April 3). AIDS May Partly Be The Consequence Of An Evolutionary Accident. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/2008/03/080331223840.htm
Society for General Microbiology. "AIDS May Partly Be The Consequence Of An Evolutionary Accident." ScienceDaily. www.sciencedaily.com/releases/2008/03/080331223840.htm (accessed July 23, 2014).

Share This




More Health & Medicine News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Idaho Boy Helps Brother With Disabilities Complete Triathlon

Idaho Boy Helps Brother With Disabilities Complete Triathlon

Newsy (July 23, 2014) An 8-year-old boy helped his younger brother, who has a rare genetic condition that's confined him to a wheelchair, finish a triathlon. Video provided by Newsy
Powered by NewsLook.com
Thousands Who Can't Afford Medical Care Flock to Free US Clinic

Thousands Who Can't Afford Medical Care Flock to Free US Clinic

AFP (July 23, 2014) America may be the world’s richest country, but in terms of healthcare, the World Health Organisation ranks it 37th. Thousands turned out for a free clinic run by "Remote Area Medical" with a visit from the Governor of Virginia. Duration: 2:40 Video provided by AFP
Powered by NewsLook.com
Stone Fruit Listeria Scare Causes Sweeping Recall

Stone Fruit Listeria Scare Causes Sweeping Recall

Newsy (July 22, 2014) The Wawona Packing Company has issued a voluntary recall on the stone fruit it distributes due to a possible Listeria outbreak. Video provided by Newsy
Powered by NewsLook.com
Huge Schizophrenia Study Finds Dozens Of New Genetic Causes

Huge Schizophrenia Study Finds Dozens Of New Genetic Causes

Newsy (July 22, 2014) The 83 new genetic markers could open dozens of new avenues for schizophrenia treatment research. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins